The meanings ascribed to the definitions and abbreviations appearing in § 199.1 and 199.2 of this title shall apply to any terms in this chapter not defined below. However, the following definitions shall apply to the terms as used in this chapter:

Emissions unit – means any part of a stationary source that emits or would have the potential to emit any regulated NSR pollutant following paragraphs (a) and (b) below:

1. (a) A new emissions unit is any emissions unit that is (or will be) newly constructed and that has existed for less than two (2) years from the date such emissions unit first operated. Any emissions unit that is constructed or installed for the purpose of replacing an existing unit, or any emissions unit that is relocated from another stationary source for the purpose of replacing an existing unit, shall be considered a new emissions unit at the time of replacement and until two (2) years from the date such new unit commenced operation; and
2. (b) An existing emissions unit is any emissions unit that is not a new emissions unit.

Major emissions unit – any emissions unit that emits or has the potential to emit the PAL pollutant in an amount that is equal to or greater than the major source threshold for the PAL pollutant as defined for a major stationary source in § 199.1 of this title.

Major modification – any physical change in or change in the method of operation of a major stationary source that would result in a significant emission increase and a significant net emissions increase of a regulated NSR pollutant from the major stationary source:

1. (a) Any emissions increase that is significant for volatile organic compounds or nitrogen oxides shall be considered significant for ozone;
2. (b) A physical change or change in the method of operation shall not include:
3. (1) Routine maintenance, repair, and replacement. In determining whether an activity at a facility constitutes routine maintenance, repair, and replacement, the owner or operator shall consider the nature, extent, purpose, frequency, and cost of the work to be performed. Routine maintenance, repair, and replacement activities are narrow in scope, do not result in increased capacity, occur with regular frequency, and involve limited expense;
4. (2) Use of an alternative fuel raw material by reason of an order under

§§ 2 (a) and (b) of the Energy Supply and Environmental Coordination Act of 1974 (15 U.S.C. §§ 791, et seq. (2006)) (or any superseding legislation) or by reason of a natural gas curtailment plan pursuant to the Federal Power Act (16 U.S.C. §§ 791a, et seq. (2006));

(3) Use of an alternative fuel by reason of an order or rule under § 125 of the Clean Air Act;

(4) Use of an alternative fuel at a steam generating unit to the extent that the fuel is generated from municipal solid waste;

(5) Use of an alternative fuel or raw material by a stationary source which;

(A) The source was capable of accommodating before December 21, 1976, unless such change would be prohibited under any federally enforceable permit condition which was established after December 12, 1976 pursuant to 40 C.F.R. § 52.21 or under regulations approved pursuant to 40 C.F.R. part 51, subpart I or 40 C.F.R. § 51.166; or

(B) The source is approved to use under any permit issued pursuant to §§ 204 or 208;

(6) A change that only consists of an increase in the hours of operation or in the production rate, unless such change is prohibited under any federally enforceable permit condition which was established after December 21, 1976 pursuant to 40 C.F.R. § 52.21 or regulations approved pursuant to 40 C.F.R. part 51, subpart I or 40 C.F.R. § 51.166; or

(7) Any change in ownership at a stationary source; and

(c) This definition shall not apply with respect to a particular pollutant when the major stationary source is complying with the requirements under § 208 for a PAL for that pollutant. Instead, the definition for PAL major modification in § 299.1 shall apply.

Net emissions increase – is as follows:

(a) With respect to any regulated NSR pollutant emitted by a major stationary source, the amount by which the sum of subparagraphs (1) and (2) below exceeds zero (0):

(1) The emissions increase from the project, determined according to the following:

1. (A) The emissions increase from the project is determined by summing the potential to emit from each new emissions unit and the difference between the potential to emit for each existing unit affected by the project after the change and the actual emissions prior to the change; and
2. (B) An emissions unit is considered affected by the project if an emissions increase from the unit would occur as a result of the project, regardless of whether a physical change or change in the method of operation will occur at the particular emissions unit; and
3. (2) Any other increases and decreases in emissions at the major stationary source that are contemporaneous with the particular change and are otherwise creditable;
4. (b) An increase or decrease in emissions is contemporaneous with the increase from the project only if it occurs during the period of five (5) consecutive calendar years before and including the date of submittal of the application and continuing until operation commences;
5. (c) An increase or decrease in emissions is creditable only if the Department or other reviewing authority has not relied on it in issuing a permit for the source under this section, which permit is in effect when the increase in emissions from the particular change occurs;
6. (d) An increase in emissions is creditable to the extent that the new level of allowable emissions exceeds the old level of actual emissions for the contemporaneous change;
7. (e) An increase that results from a physical change at a source occurs when the emissions unit on which construction occurred becomes operational and begins to emit a particular pollutant. Any replacement unit that requires shakedown becomes operational only after a reasonable shakedown period, not to exceed one hundred eighty (180) days;
8. (f) A decrease in emissions is credible, to the extent that:
9. (1) The old level of actual emissions exceeds the new level of allowable emissions;
10. (2) The new level of allowable emissions is enforceable as a practical matter at and after the time that actual construction on the particular change begins;

(3) The Department has not relied on it in issuing any permit under regulations approved pursuant to 40 C.F.R. part 51, subpart I or the State has not relied on it in demonstrating attainment or reasonable further progress; and

(4) The decrease in emissions has approximately the same qualitative significance for public health and welfare as that attributed to the increase from the particular change; and

(g) Actual emissions for calculating increases and decreases under this paragraph shall be determined as defined in § 199.1 of this title.

Plantwide applicability limit (PAL) – an emission limitation, expressed in tons per year, for a pollutant at a major stationary source that is federally enforceable and enforceable as a practical matter established source-wide in accordance with § 208.

PAL baseline emissions – the rate of emissions, in tons per year, of a single regulated NSR pollutant:

(a) For any emissions unit that was an existing emissions unit during the PAL baseline period, PAL baseline emissions means the average rate, in tons per year, at which the unit actually emitted the pollutant during the PAL baseline period;

(1) The average rate shall include fugitive emissions to the extent quantifiable and any authorized emissions associated with startup and shutdown;

(2) The average rate shall not include excess emissions or emissions associated with upsets or malfunctions;

(3) The average rate shall be adjusted downward to exclude any non-compliant emissions that occurred while the source was operating above any emission limitation that was legally enforceable during the PAL baseline period;

(4) The average rate shall be adjusted downward to exclude any emissions that would have exceeded an emission limitation with which the major stationary source must currently comply, had such major stationary source been required to comply with such limitations during the PAL baseline period; and

(5) The average rate shall not be based in any period for which there is inadequate information either for determining emissions, in tons per year, or for adjustments required by subparagraphs (1) through

(4) above; and

1. (b) For any existing emissions unit that was not an existing emissions unit during the PAL baseline period but commenced operation during or after the selected PAL baseline period, the PAL baseline emissions shall equal the allowable emissions or the potential to emit, whichever is lower;
2. (c) For a new emissions unit, PAL baseline emissions shall equal zero (0); and
3. (d) PAL baseline emissions shall be determined by measurement, calculations, estimations, or recordkeeping in the order of the following preferences:
4. (1) Continuous Emission Monitoring System (CEMS) data integrated to annual emissions using flow meters and conversion factors;
5. (2) Predictive Emissions Monitoring System (PEMS);

6. (3) Other Measurements and Calculations:

   1. (A) Stack emissions:
   2. (i) Determine hourly emissions by stack emission testing;
   3. (ii) Determine annual operating hours using hour meter records; and
   4. (iii) Calculate annual emissions using hourly emissions and annual operating hours; or
   5. (iv) Determine emissions per heat input by stack emission testing;
   6. (v) Determine amount of fuel combusted in a year using fuel flow meter record and calculate annual heat input; and
   7. (vi) Calculate annual emissions using emissions per heat input and annual heat input;
   8. (B) Mass balance:
   9. (i) Determine the amount of materials used through measurements in the process;

7. (ii) Calculate emissions per mass of material used using mass balance techniques;

8. (iii) Determine amount of material used in a year; and
9. (iv) Calculate annual emissions using emissions per mass of material and amount of material used in a year;(C) Emission Factors:- (i) Using generally recognized and accepted emission factors such as AP-42, determine hourly emissions;
10. (ii) Determine annual operating hours using hour meter records; and
11. (iii) Calculate annual emissions using hourly emissions and annual operating hours; or
12. (iv) Using generally recognized and accepted emission factors such as AP-42, determine emissions per heat input unit;
13. (v) Determine amount of fuel combusted in a year using fuel flow meter record and calculate annual heat input; and
14. (vi) Calculate annual emissions using emissions per heat input and annual heat input; or(4) Instances where measurements of operating hours or fuel combusted (hour meter or fuel flow meter) are not available, annual emissions can be calculated using available records (such as production records, fuel consumption records, fuel purchase receipts, laboratory reports on fuel analysis, and third party records such as electric bills):- (A) Determine hourly emissions using stack emission tests, mass balance or emission factors;
15. (B) Determine annual hours of operation using production records; and
16. (C) Calculate annual emissions using hourly emissions and annual hours of operation; or

(D) Determine emissions per heat input unit using stack emission tests, mass balance or emission factors;

(E) Determine amount of fuel combusted in a year records and calculate annual heat input; and

(F) Calculate annual emissions using emissions per heat input and annual heat input.

PAL baseline period – the two (2) consecutive calendar years immediately prior to the year the application for a PAL is submitted. The Department may allow the use of a different consecutive twenty-four (24) month period within the last five (5) years upon a determination that the operations during that period would be more representative of normal source operations.

PAL effective date – generally means the date of issuance of the PAL permit. However, the PAL effective date for an increased PAL is the date any emissions unit that is part of the PAL major modification becomes operational and begins to emit the PAL pollutant. The PAL limit that was in effect prior to the change shall remain in effect until the new PAL is effective.

PAL major modification – notwithstanding the definitions for major modification and net emissions increase in § 199.1, any physical change in or change in the method of operation of the PAL source that causes it to emit the PAL pollutant at a level greater than the PAL.

PAL pollutant – the pollutant for which a PAL is established at a major stationary source.

Predictive emissions monitoring system (PEMS) – all of the equipment necessary to monitor process and control device operational parameters (for example, control device secondary voltages and electric currents) and other information (for example, gas flow rate, O₂ or CO₂ concentrations), and calculate and record the mass emissions rate (for example, lb/hr) on a continuous basis.

Regulated NSR (new source review) pollutant – is the following:

(a) Nitrogen oxides or any volatile organic compounds;

(b) Any pollutant for which a national ambient air quality standard has been promulgated;

(c) Any pollutant that is a constituent or precursor of a general pollutant listed under paragraphs (a) or (b) above, provided that a constituent or precursor pollutant may only be regulated under NSR as part of regulation of the general

pollutant;

(d) Precursors identified by the Administrator for purposes of NSR are the following:

(1) Volatile organic compounds and nitrogen oxides are precursors to ozone in all ozone nonattainment areas;

(2) Sulfur dioxide is a precursor to PM₂.₅ in all PM₂.₅ nonattainment areas;

(3) Nitrogen oxides are presumed to be precursors to PM₂.₅ in all PM₂.₅ nonattainment areas, unless the Department demonstrates to the Administrator's satisfaction or EPA demonstrates that emissions of nitrogen oxides from sources in a specific area are not a significant contributor to that area's ambient PM₂.₅ concentrations; and

(4) Volatile organic compounds and ammonia are presumed not to be precursors to PM₂.₅ in any PM₂.₅ nonattainment area, unless the Department demonstrates to the Administrator's satisfaction or EPA demonstrates that emissions of volatile organic compounds or ammonia from sources in a specific area are a significant contributor to that area's ambient PM₂.₅ concentrations; and

(e) PM₂.₅ emissions and PM₁₀ emissions shall include gaseous emissions from a source or activity which condense to form particulate matter at ambient temperatures, determined in accordance with the following:

(1) Such condensable particulate matter shall be accounted for in applicability determinations and in establishing emissions limitations for PM₂.₅ and PM₁₀ in nonattainment major NSR permits; and

(2) Compliance with emissions limitations for PM₂.₅ and PM₁₀ shall not be based on condensable particulate matter unless required by the terms and conditions of the permit or the applicable implementation plan. Applicability determinations made prior to this date without accounting for condensable particulate matter shall not be considered in violation of this section unless the applicable implementation plan required condensable particulate matter to be included.

Significant – in reference to a significant emissions increase, a significant net emissions increase, or the potential of a stationary source or emissions unit to emit a significant amount of a regulated NSR pollutant, a rate of emissions that would equal or exceed any of the following:

(a) Carbon monoxide: one hundred tons per year (100 Tpy);

(b) Ozone - Nitrogen oxides or VOCs: twenty-five (25) Tpy;

(c) Sulfur dioxide: forty (40) Tpy;

(d) Lead: six-tenths (0.6) Tpy;

(e) PM₁₀: fifteen (15) Tpy;

(f) PM₂.₅: ten (10) Tpy;

(g) For the purposes of applying the requirements of this section, where applicable, to a major stationary source of a PM₁₀ precursor located in a PM₁₀ nonattainment area, the significant emission rate for a PM₁₀ precursor is forty (40) Tpy or more of that precursor;

(h) For the purposes of applying the requirements of this section, the significant emission rate for a PM₂.₅ precursor is forty (40) Tpy of sulfur dioxide emissions and forty (40) Tpy of nitrogen oxide emissions;

(i) Notwithstanding the significant emissions rate for carbon monoxide stated above, significant for carbon monoxide in a serious nonattainment area is fifty (50) Tpy, provided the Department has determined that the applicable stationary source contributes significantly to carbon monoxide levels in that area;

(j) Notwithstanding the significant emissions rates for ozone stated above, significant for volatile organic compounds in an extreme nonattainment area for ozone is any amount above zero; and

(k) Notwithstanding the above paragraphs, any emissions rate or any net emissions increase associated with a major stationary source or major modification, which would construct within six and twenty-one hundredths miles (6.21 m.), or ten kilometers (10 km), of any Class I area, and have an impact on the area equal to or greater than one microgram per cubic meter (1 µg/m³) over a twenty-four hour (24 hr) average.

Significant emissions increase – for a regulated NSR pollutant, an increase in emissions that is significant (as defined in this section) for that pollutant.

Significant emissions unit – an emissions unit that emits or has the potential to emit a PAL pollutant in an amount that is equal to or greater than the significant level (as defined under “significant” in this subsection or in the Clean Air Act, whichever is lower) for that PAL pollutant.

Small emissions unit – an emissions unit that emits or has the potential to emit the PAL pollutant in an amount less than the significant level (as defined under “significant” in this subsection or in the Clean Air Act, whichever is lower) for that PAL pollutant.

Source category permit – a preconstruction or operating permit issued by the Department that may be applied to a number of similar emissions units or sources. A source category permit may be written to address a single emissions unit, a group of the same type of emissions units, or an entire minor source.

SOURCE: Final Rulemaking published at 59 DCR 13044 (November 16, 2012).